This invention relates to the carbonization of natural carbonaceous materials. In one of its more particular aspects this invention relates to a process for optimizing carbonization reactions such as the production of graphite or coke.
It is known that certain graphite or coke precursors are more readily carbonized to produce better products or to produce such products in better yields than others. It is also known that the microstructure and properties of carbonized materials are determined by the characteristics of an ordered fluid, termed the "carbonaceous mesophase", which forms during pyrolysis, usually between the temperatures of 370.degree. C. and 500.degree. C. It is the order developed in this mesophase that determines the properties of the final product obtained, for example, after heating to graphitizing temperatures of 2800.degree. C. The mesophase in carbonaceous materials which graphitize displays an optically anisotropic microstructure, from which the properties of the carbonized product can be predicted. An isotropic microstructure, on the other hand, indicates a non-graphitizing carbon. The characteristics of the final product thus are controlled by the mesophase formed below 500.degree. C. These characteristics can be determined in a qualitative way by microscopic analysis using a cross-polarizing microscope at various stages of the pyrolysis.
Although the need for optimizing the chemical composition of precursors for graphite and coke formation has long been appreciated, precisely what chemical compositions might be considered optimum and how to provide such optimal chemical composition from readily available candidate precursor materials have until now been unattained goals.
It is accordingly an object of the present invention to provide a means for selecting precursors for graphite and coke formation.
Another object of this invention is to provide a means for optimizing mesophase formation during the carbonization of precursor materials.
Another object of this invention is to provide a means for furnishing precursors which will form mesophase upon suitable treatment.
Other objects and the advantages of this invention will become apparent in the course of the following detailed description.